I've heard o disconnect the negative battery in the past so a voltage spike will not fry electronics. Now that I have to weld my exhaust I looked into it again, I read the opposite is true. WHat do the experts say?

 

Ive welded several things on a car without touching the battery. Exhaust, body, frame ect ect.

 

Same as above with no issues ever

 

i just do it because it takes less than 2 minutes to do.

 

Have seen a couple fry the PCM when not disconnected, and at the same time I know of hundreds that have no issue. Your gamble, I would unhook it.

 

I've seen the HEI ignition module fry on an older car. So I now disconnect the battery. It sounds like your asking if there could be harm by NOT doing that as well...good question! I would venture a guess that it would be much harder to complete a circuit to the electrical systems through a body-mounted box or fuse panel, etc. with the battery disconnected even still though.

 

99% of the times somebody FUBARs an electrical system is because they didn't know squat about placing the ground clamp. The last one I saw dead, some doodoo head had hooked the ground clamp up to the main battery ground strap under the engine and then welded on the rear of the car.

Just clamp on the pipe near the weld site and you'll be fine.

 

Exhaust shops rarely disconnect the battery, but it doesn't hurt, only takes a minute.

 

I have welded on a bunch of cars/trucks, never disconnected the batt

 

I've always put the ground cable on the piece in welding and never had an issue.